Return the most recent record from ElasticSearch index

Do you have _timestamp enabled in your doc mapping?

{
    "doctype": {
        "_timestamp": {
            "enabled": "true",
            "store": "yes"
        },
        "properties": {
            ...
        }
    }
}

You can check your mapping here:

http://localhost:9200/_all/_mapping

If so I think this might work to get most recent:

{
  "query": {
    "match_all": {}
  },
  "size": 1,
  "sort": [
    {
      "_timestamp": {
        "order": "desc"
      }
    }
  ]
}